RT Journal Article
SR Electronic
T1 Fast Grip Force Adaptation To Friction Relies On Localized Fingerpad Strains
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.07.20.452911
DO 10.1101/2021.07.20.452911
A1 Schiltz, Félicien
A1 Delhaye, Benoit P.
A1 Crevecoeur, Frédéric
A1 Thonnard, Jean-Louis
A1 Lefèvre, Philippe
YR 2021
UL http://biorxiv.org/content/early/2021/07/20/2021.07.20.452911.abstract
AB Humans can quickly adjust their grip force to a change in friction at the object-skin interface during dexterous manipulation in a precision grip. To perform this adjustment, they rely on the feedback of the mechanoreceptive afferents innervating the fingertip skin. Because these tactile afferents encode information related to skin deformation, the nature of the feedback signaling a change in friction must somehow originate from a difference in the way the skin deforms when manipulating objects of different frictions. To better characterize the origin of the underlying sensory events, we asked human participants to perform a grip-lifting task with a manipulandum equipped with an optical imaging system. This system enabled to monitor fingertip skin strains through transparent plates of glass that had different levels of friction. We observed that, following an unexpected change in friction, participants adapted their grip force within 370ms after contact with the surface. By comparing the deformation patterns when unexpectedly switching from a high to a low friction condition, we found a significant increase in skin deformation inside the contact area arising over 100ms before the motor response, during the loading phase, suggesting that local and partial deformation patterns prior to lift-off are used in the nervous system to adjust the grip force as a function of the frictional condition.Competing Interest StatementThe authors have declared no competing interest.